Narrative:

On fri afternoon, 1/88 at approximately 0a00z, I obtained a WX briefing from FSS and filed an IFR flight plan for a flight from cheyenne to den. We filed cheyenne to den, dir at 11000', scheduled to depart at 0a45z. After engine start, we were given a revised routing, (V-19 to winie intersection, and from there to den, dir) and departed runway 30 at approximately 0b10z. The flight was uneventful (in and out of patchy IMC, cloud, but no precipitation) until just north 5-10 mins of den, on a heading of 171 degrees, at which point we heard a loud pop or snap in the cabin and noticed a dual alternator failure indication (2 red lights) on the panel. We downloaded all unnecessary electrical equipment, but were unable to bring the system back on line. We immediately advised approach of our problem. We were then just north of the final approach course for the ILS 17L (which was also active). We were advised to expect the ILS DME 8R and to continue inbound. We were then vectored, (first southwest 210 degrees, then south 190 degrees, then southeast 100 degrees) to intercept the ILS runway 8R (078 degree heading) and told to maintain 8000'. As we flew the assigned vectors, at one point approach asked for confirmation that we were at 8000', our assigned. When we confirmed that we were 'at 8,' approach advised that we were showing a 2000' discrepancy and instructed us to stop squawking our mode C, which we immediately did. Shortly thereafter, we were turned to the intercept (100 degrees) course for the ILS (078 degree), clrd for the ILS runway 8R and told to maintain 8000', 'until established.' as we became established, we were advised that we were '4 miles outside the marker, clrd for the ILS 8R, go to tower, 118.3.' I called tower and advised of our position and that we had been 'clrd for the ILS 8R.' receiving no response, I called again, this time to advise that we were 'just outside' the marker and 'clrd for the ILS.' at this point, I heard tower call: 'small transport, stapleton tower, are you on frequency?' I responded that we were 'on frequency,' at the marker, clrd for the ILS, 8R, and had 'smoke in the cabin,' which I had begun to notice. Tower again called back: 'small transport, stapleton tower, are you on frequency?' tower then became broken up, advised what I thought was 'clrd to land,' and became totally unreadable, and finally fell silent. During this approach phase, I went through the prelndg check, dropped the first notch of flaps, turned on the boost pumps and dropped the gear. We heard the gear motor go through what sounded like its normal cycle. I saw the gear transition light come on and go off and thought that I saw the '3 greens.' during this sequence, however, we lost all electrical power. In my scan, I noticed all red flags on the ILS CDI and GS, all radio and panel lights were out. We had already been using flashlights and continued to do so. The smoke was becoming more noticeable. We had no forward visibility. We were still completely IMC. In a glance over the side, through a small hole, I saw the airport environment below. I dropped down further and broke out high to the north of the final approach course, and very close to the touchdown end of 8R. I turned for the runway and, on short final, dropped the level for the second notch of flaps. As it turned out, although I didn't then know it, they did not come down any further. By then the smoke in the cabin was getting thicker. The thought flashed through my mind to check for gear extension manually and I started to do so. The procedure calls for a pulling of the gear motor circuit breaker and a cranking of the gear handle (which is stowed behind the copilot's seat) 50 complete (360 degree) counter-clockwise turns. I knew that there simply wasn't enough time to do it. With no navigation/communication or other electrical power, we could not stay airborne any longer. We could not climb back into the soup for any reason. We simply could not fly around the stapleton airport environment in and out of a ragged ceiling at night with no navigation or communication, with smoke in the cockpit and with simultaneous 17L and 8R ILS approachs in progress, all for the purpose of attempting to manually ascertain full gear extension. We had to land. As wetouched down I felt, first, a strange vibration and then a sickening feeling as I felt the gear collapse under us and we began to skid down the runway. As we finally skidded to stop, while attempting to keep the aircraft on the center of the runway (it was skidding to the right), I shut down the switches, fuel and mags, and we started to climb out. We had difficulty getting the door open and, by now, the smoke was billowing out from under the panel. Just as I was about to give up on the front door and climb over the back seat to try to get the rear door open, we were able to get the front door open, my passenger's seatbelt off and both of us out of the airplane. As we ran clear, I was concerned that aircraft which we now could see on final behind us would not see us. I started to run back to get a flashlight with which to signal, but realized how foolish and futile that would be. We simply hoped that the aircraft would see us and go around. As it turned out, it broke off its approach and flew a low pass up the runway overhead. Shortly thereafter, we were reached by the emergency crews. We arranged for the aircraft's removal and storage and reported the incident. There were no injuries. The aircraft was substantially damaged, perhaps totally lost. Although at this time the cause of the electrical failure is unknown, I suspect a short in the electrical system caused by the electric propeller deice. The timer for the propeller deice had been replaced approximately 3 weeks earlier and had not been used in flight for any sustained period of time until the night of the incident. The circuit breaker for this system, which was then in use, was tripped (switch off). The timer is located in an area under the panel from where I thought I heard the pop originate. I believe that an alternate battery bus should be standard equipment in aircraft of the type in question, and that all aircraft flying IFR should have a hand-held portable navigation/communication radio onboard as standard equipment.

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Original NASA ASRS Text

Title: DUAL ALTERNATOR FAILURE UNDER IFR CONDITIONS. GEAR COLLAPSE ON LNDG.

Narrative: ON FRI AFTERNOON, 1/88 AT APPROX 0A00Z, I OBTAINED A WX BRIEFING FROM FSS AND FILED AN IFR FLT PLAN FOR A FLT FROM CHEYENNE TO DEN. WE FILED CHEYENNE TO DEN, DIR AT 11000', SCHEDULED TO DEPART AT 0A45Z. AFTER ENG START, WE WERE GIVEN A REVISED ROUTING, (V-19 TO WINIE INTXN, AND FROM THERE TO DEN, DIR) AND DEPARTED RWY 30 AT APPROX 0B10Z. THE FLT WAS UNEVENTFUL (IN AND OUT OF PATCHY IMC, CLOUD, BUT NO PRECIPITATION) UNTIL JUST N 5-10 MINS OF DEN, ON A HDG OF 171 DEGS, AT WHICH POINT WE HEARD A LOUD POP OR SNAP IN THE CABIN AND NOTICED A DUAL ALTERNATOR FAILURE INDICATION (2 RED LIGHTS) ON THE PANEL. WE DOWNLOADED ALL UNNECESSARY ELECTRICAL EQUIP, BUT WERE UNABLE TO BRING THE SYS BACK ON LINE. WE IMMEDIATELY ADVISED APCH OF OUR PROB. WE WERE THEN JUST N OF THE FINAL APCH COURSE FOR THE ILS 17L (WHICH WAS ALSO ACTIVE). WE WERE ADVISED TO EXPECT THE ILS DME 8R AND TO CONTINUE INBND. WE WERE THEN VECTORED, (FIRST SW 210 DEGS, THEN S 190 DEGS, THEN SE 100 DEGS) TO INTERCEPT THE ILS RWY 8R (078 DEG HDG) AND TOLD TO MAINTAIN 8000'. AS WE FLEW THE ASSIGNED VECTORS, AT ONE POINT APCH ASKED FOR CONFIRMATION THAT WE WERE AT 8000', OUR ASSIGNED. WHEN WE CONFIRMED THAT WE WERE 'AT 8,' APCH ADVISED THAT WE WERE SHOWING A 2000' DISCREPANCY AND INSTRUCTED US TO STOP SQUAWKING OUR MODE C, WHICH WE IMMEDIATELY DID. SHORTLY THEREAFTER, WE WERE TURNED TO THE INTERCEPT (100 DEGS) COURSE FOR THE ILS (078 DEG), CLRD FOR THE ILS RWY 8R AND TOLD TO MAINTAIN 8000', 'UNTIL ESTABLISHED.' AS WE BECAME ESTABLISHED, WE WERE ADVISED THAT WE WERE '4 MILES OUTSIDE THE MARKER, CLRD FOR THE ILS 8R, GO TO TWR, 118.3.' I CALLED TWR AND ADVISED OF OUR POS AND THAT WE HAD BEEN 'CLRD FOR THE ILS 8R.' RECEIVING NO RESPONSE, I CALLED AGAIN, THIS TIME TO ADVISE THAT WE WERE 'JUST OUTSIDE' THE MARKER AND 'CLRD FOR THE ILS.' AT THIS POINT, I HEARD TWR CALL: 'SMT, STAPLETON TWR, ARE YOU ON FREQ?' I RESPONDED THAT WE WERE 'ON FREQ,' AT THE MARKER, CLRD FOR THE ILS, 8R, AND HAD 'SMOKE IN THE CABIN,' WHICH I HAD BEGUN TO NOTICE. TWR AGAIN CALLED BACK: 'SMT, STAPLETON TWR, ARE YOU ON FREQ?' TWR THEN BECAME BROKEN UP, ADVISED WHAT I THOUGHT WAS 'CLRD TO LAND,' AND BECAME TOTALLY UNREADABLE, AND FINALLY FELL SILENT. DURING THIS APCH PHASE, I WENT THROUGH THE PRELNDG CHK, DROPPED THE FIRST NOTCH OF FLAPS, TURNED ON THE BOOST PUMPS AND DROPPED THE GEAR. WE HEARD THE GEAR MOTOR GO THROUGH WHAT SOUNDED LIKE ITS NORMAL CYCLE. I SAW THE GEAR TRANSITION LIGHT COME ON AND GO OFF AND THOUGHT THAT I SAW THE '3 GREENS.' DURING THIS SEQUENCE, HOWEVER, WE LOST ALL ELECTRICAL PWR. IN MY SCAN, I NOTICED ALL RED FLAGS ON THE ILS CDI AND GS, ALL RADIO AND PANEL LIGHTS WERE OUT. WE HAD ALREADY BEEN USING FLASHLIGHTS AND CONTINUED TO DO SO. THE SMOKE WAS BECOMING MORE NOTICEABLE. WE HAD NO FORWARD VIS. WE WERE STILL COMPLETELY IMC. IN A GLANCE OVER THE SIDE, THROUGH A SMALL HOLE, I SAW THE ARPT ENVIRONMENT BELOW. I DROPPED DOWN FURTHER AND BROKE OUT HIGH TO THE N OF THE FINAL APCH COURSE, AND VERY CLOSE TO THE TOUCHDOWN END OF 8R. I TURNED FOR THE RWY AND, ON SHORT FINAL, DROPPED THE LEVEL FOR THE SECOND NOTCH OF FLAPS. AS IT TURNED OUT, ALTHOUGH I DIDN'T THEN KNOW IT, THEY DID NOT COME DOWN ANY FURTHER. BY THEN THE SMOKE IN THE CABIN WAS GETTING THICKER. THE THOUGHT FLASHED THROUGH MY MIND TO CHK FOR GEAR EXTENSION MANUALLY AND I STARTED TO DO SO. THE PROC CALLS FOR A PULLING OF THE GEAR MOTOR CB AND A CRANKING OF THE GEAR HANDLE (WHICH IS STOWED BEHIND THE COPLT'S SEAT) 50 COMPLETE (360 DEG) COUNTER-CLOCKWISE TURNS. I KNEW THAT THERE SIMPLY WASN'T ENOUGH TIME TO DO IT. WITH NO NAV/COM OR OTHER ELECTRICAL PWR, WE COULD NOT STAY AIRBORNE ANY LONGER. WE COULD NOT CLB BACK INTO THE SOUP FOR ANY REASON. WE SIMPLY COULD NOT FLY AROUND THE STAPLETON ARPT ENVIRONMENT IN AND OUT OF A RAGGED CEILING AT NIGHT WITH NO NAV OR COM, WITH SMOKE IN THE COCKPIT AND WITH SIMULTANEOUS 17L AND 8R ILS APCHS IN PROGRESS, ALL FOR THE PURPOSE OF ATTEMPTING TO MANUALLY ASCERTAIN FULL GEAR EXTENSION. WE HAD TO LAND. AS WETOUCHED DOWN I FELT, FIRST, A STRANGE VIBRATION AND THEN A SICKENING FEELING AS I FELT THE GEAR COLLAPSE UNDER US AND WE BEGAN TO SKID DOWN THE RWY. AS WE FINALLY SKIDDED TO STOP, WHILE ATTEMPTING TO KEEP THE ACFT ON THE CENTER OF THE RWY (IT WAS SKIDDING TO THE RIGHT), I SHUT DOWN THE SWITCHES, FUEL AND MAGS, AND WE STARTED TO CLB OUT. WE HAD DIFFICULTY GETTING THE DOOR OPEN AND, BY NOW, THE SMOKE WAS BILLOWING OUT FROM UNDER THE PANEL. JUST AS I WAS ABOUT TO GIVE UP ON THE FRONT DOOR AND CLB OVER THE BACK SEAT TO TRY TO GET THE REAR DOOR OPEN, WE WERE ABLE TO GET THE FRONT DOOR OPEN, MY PAX'S SEATBELT OFF AND BOTH OF US OUT OF THE AIRPLANE. AS WE RAN CLR, I WAS CONCERNED THAT ACFT WHICH WE NOW COULD SEE ON FINAL BEHIND US WOULD NOT SEE US. I STARTED TO RUN BACK TO GET A FLASHLIGHT WITH WHICH TO SIGNAL, BUT REALIZED HOW FOOLISH AND FUTILE THAT WOULD BE. WE SIMPLY HOPED THAT THE ACFT WOULD SEE US AND GO AROUND. AS IT TURNED OUT, IT BROKE OFF ITS APCH AND FLEW A LOW PASS UP THE RWY OVERHEAD. SHORTLY THEREAFTER, WE WERE REACHED BY THE EMER CREWS. WE ARRANGED FOR THE ACFT'S REMOVAL AND STORAGE AND RPTED THE INCIDENT. THERE WERE NO INJURIES. THE ACFT WAS SUBSTANTIALLY DAMAGED, PERHAPS TOTALLY LOST. ALTHOUGH AT THIS TIME THE CAUSE OF THE ELECTRICAL FAILURE IS UNKNOWN, I SUSPECT A SHORT IN THE ELECTRICAL SYS CAUSED BY THE ELECTRIC PROP DEICE. THE TIMER FOR THE PROP DEICE HAD BEEN REPLACED APPROX 3 WKS EARLIER AND HAD NOT BEEN USED IN FLT FOR ANY SUSTAINED PERIOD OF TIME UNTIL THE NIGHT OF THE INCIDENT. THE CB FOR THIS SYS, WHICH WAS THEN IN USE, WAS TRIPPED (SWITCH OFF). THE TIMER IS LOCATED IN AN AREA UNDER THE PANEL FROM WHERE I THOUGHT I HEARD THE POP ORIGINATE. I BELIEVE THAT AN ALTERNATE BATTERY BUS SHOULD BE STANDARD EQUIP IN ACFT OF THE TYPE IN QUESTION, AND THAT ALL ACFT FLYING IFR SHOULD HAVE A HAND-HELD PORTABLE NAV/COM RADIO ONBOARD AS STANDARD EQUIP.

Data retrieved from NASA's ASRS site as of August 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.